Toast the hazelnuts in the oven for 5-10 minutes until fragrant, golden and the skins are coming loose. Leave to cool slightly, then rub off most of the skins and grind to a fine meal in a food processor or blender (it’s ok if there are still a few slightly bigger bits left)
Combine the ground hazelnuts in a bowl with the flours, spices, baking soda and salt.
Whisk together the dark brown sugar, caster sugar and olive oil until combined. Add the eggs, one at a time, until fully combined. Add the fresh ginger and whisk to combine.
Add the dry ingredients and fold in to just combine. Add the pear and fold in to combine.
Bake for 50min - 1hr until a skewer inserted in the centre comes out clean.
Leave to cool completely.
Combine the room temperature cream cheese and butter in a bowl of a stand mixer and beat with the paddle attachment until smooth and creamy.
Add the sifted icing sugar, maple syrup and salt and beat to combine. Taste and adjust maple syrup and salt if needed.
Spread onto the cooled cake and decorate as you like - I made some salted caramel (I made a half batch of the recipe here, and leftovers freeze very well) and used chopped hazelnuts and dried pear (available from specialty bulk food stores)